The Breast Tomosynthesis
The breast tomosynthesis
To defeat breast cancer, prevention remains the key weapon. In this sense, the adoption of breast tomosynthesis, the advanced technology used in breast prevention is essential for all women.
It is in practice a three-dimensional high definition mammography. It is a major step forward for the most advanced technology for the prevention of breast cancer. Further help of great interest for the early diagnosis of the breast disease.
“Tomosynthesis is a diagnostic tool that allows us to study the breast ‘layered’ – confirms Dr. Gianluca Pazzaglia, Head of the Breast Center of Perugia – precisely where the breast is broken down into many images that then, superimposed, reconstruct the figure breast in its entirety. All this translates into a huge advantage for those breasts difficult to examine – for example in dense breasts – which can then be analyzed more specifically and in detail, revealing lesions that in the overall image would otherwise be covered. The result is that it increases the diagnostic accuracy, as they can be identified lesions that would be ‘invisible’ with the traditional examination “.
A determining factor for a correct prevention of breast cancer, because the problem of breast cancer is resolved through a good diagnosis that should have been done early – so the female controls must be frequent – but must also be correct, conducted by competent persons and with advanced equipment, modern and up to date as it should occur in all breast imaging centers. ”
According to the latest data on the incidence and prevalence of breast cancer in Italian women the number of new breast cancers are about more than 40.000 per year, with an increasing trend: there were 41.608 in 2000 and in 6 years there has been a growth of 13,8%; the largest percentage increase in the number of new breast cancers are found in women aged between 25 and 44 years old (almost 77 per 100.000 women in this age group, with an increase of +28,6% in six years).
From a methodological point of view this machine of the latest generation offers a performance similar to a digital mammography, but it is less painful because the necessary compression is less. The cost of the examination is practically the same; it remains unchanged the exposure time and also the increase of radiation absorbed is absolutely negligible. Compared to the standard methodology 2D examination, however, the study performed with 3D tomosynthesis allows a much more accurate “bit by bit” of the breast. Although to date there are still no scientific studies comparing the diagnostic tools in breast “everything suggests – says Dr. Pazzaglia – that tomography may soon play an important role in modern integrated breast imaging diagnostic process.”
BREAST TOMOSYNTHESIS – TECHNICAL EVALUATION
The digital breast tomosynthesis (DBT) and an imaging three-dimensional technique that allows the reconstruction of volumetric images of the breast from a finite number of two-dimensional projections low doses, obtained with different angles of the X-ray tube. The principle geometric radio of tomosynthesis and similar to that applied in the old stratigraphic technique, with the fundamental difference that, while the stratigraphy required the acquisition of multiple exposures for each layer that you wanted to “focus”, the digital tomosynthesis allows to reconstruct an arbitrary number of floors from the same sequence of two-dimensional projections.
This is made possible by the separation between the process of acquisition and visualization mode allowed by the use of direct digital detectors for which the same raw projections can be processed to reconstruct different floors. The volumetric reconstruction, in principle, allows to overcome one of the main limitations of imaging two-dimensional, or the masking of lesions (in the case of breast, masses, microcalcifications, etc..), caused by the superposition of normal structures; then the opportunity to dissociate different floors by the tomosynthesis suggests a possible reduction in the number of false negative and false positive results due to overlap [3-5]. As introduced, the main limitation of two-dimensional mammography in Screen Film (SFM = Screen Film Mammography) and in digital (FFDM = Full Field Digital Mammography) is due to the breast high density of the anatomical substrate resulting from the superposition of different “structures”.
It is intuitive that high thickness can produce on a surface an “effect of high density,” although between the glandular structures there are floors of fat more or less extensive. In presence of these conditions it follows the failure or poor visualization and the “non-perception” of expansive lesions (masses and distortions) and calcifications, with error significantly more relevant to the expansive lesions in relation to the lower intrinsic contrast. By virtue of a “clear representation” in the absence of overlaps, tomosynthesis is unable to “make visible” and/or better analyzed in shape, in outline, in the arrangement and number of the lesions “not represented or misrepresented” by mammography. The DBT allows a substantial improvement in the detection and analysis of injury, affecting much of their presence on the belief in the certainty of their absence as compared to FFDM.
This, however, is associated with a longer time of reading, related to the number of images and the information content significantly larger of the same to be examined carefully in relation to the analysis of layer and in space recomposition by the operator doctor. The DBT is not able, at present, to define with sufficient accuracy the quadrant in which the lesion is located. Tomographic detection allows you to appreciate that most injuries in isolation “suffer” the overlap and hence the confusion of layers to standard mammography. If the first comparative results, for now small, are confirmed, the DBT will enter fully into the category of appropriate techniques to study breast aimed at detecting lesions both in the diagnostic breast and in screening.